A huge potato bass

Just getting to Rocktail Bay is an adventure in itself. After an internal flight from Johannesburg, I was greeted at the tiny Richards Bay airport by Dirk Adendorff, a missionary pilot who works for the Zululand Mission Air Transport. ZUMAT flies single-engined aircraft around the bush strips of KwaZulu Natal, delivering flying doctors and picking up emergency medical cases from the poor rural villages for transportation to the nearest decent hospital.

Dirk whisked me through the queues at airport security with the brazen cry of 'private flight - one passenger coming through!' In a few minutes we were airborne, skimming along the stunning Natal coastline at less than 500ft.

Giant sand dunes separated the dark blue Indian Ocean from the inland plains and Dirk soon proved himself to be an expert game-spotter. 'Turtle!' he would yell into the headset, and bank the plane so that I could glimpse the speck in the sea below.

Through the water, I could clearly make out the patchwork of reefs below. 'Whales!' was Dirk's next communication, and sure enough, half a mile from the beach I could see humpback whales spouting. Three or four times he cruised low over the sea to give me a glimpse of the whales as they ploughed through the water on their way to give birth in the Mozambique Channel.

After a while we moved inland, and then it was 'Crocodiles!', 'Hippos!' and 'Zebra!'. By the time we landed at Rocktail Bay, I felt like Meryl Streep in Out of Africa. Surely the diving could not live up to such an introduction?

Rocktail Bay lies inside the Maputoland Coastal Forest & Marine Reserve. Administered by the KwaZulu Natal Wildlife Service, it is subject to strict environmental protection. Only one diving boat is allowed on the 37 mile stretch of coastline either side of Rocktail Bay, and diving on the reefs is exclusively licensed to Wilderness Safaris.

Because the area is an important nesting site for turtles, the dive-boat can launch only two hours before or after low tide, to avoid vehicles driving on the sand at high-water mark and disturbing their eggs. On my visit, that meant being woken at 5am to make the 10 mile drive to Island Rock.

A dawn start is no hardship at Rocktail Bay. Getting to the RIB's launching site involves driving by 4x4 along the deserted golden beach as the sun christens the glistening waves. As if that wasn't enough of a consolation, five minutes after a surf launch I was in the water snorkelling with three bottlenose dolphins. When they had had enough of playing with me, it was time to see what the reefs were like.

Snappers and sweetlips. Kingfish and chub. Octopus and mantis shrimp. A giant guitar shark and a potato bass weighing 70kg. On a magnificent black tree coral I spotted three secretive long-nosed hawkfish, four species of nudibranch and a host of seastars. There were giant leopard cowries nestled in between coral heads and geometric eels poking their heads from openings in the reef at every turn. And all on a carpet of coral without any bleaching or obvious damage of any description.

At the end of the first dive, my computer was already starting to complain. On our safety stop we saw not one but two loggerhead turtles ascending for air. Back on the boat, I realised how close I had come to making a big mistake. I almost hadn't come to Rocktail Bay, assuming that, like my previous South African diving experiences, it would be distinctly underwhelming. How wrong could I have been?

Darryl Smith, who runs the diving at Rocktail with his wife Debbie, was our skipper. Having worked for the Natal Sharks Board for 15 years, he knows his fish. 'This area is special, and we aim to keep it like that,' he explained as we ate the breakfast provided by the lodge.

In between mouthfuls of sausage, home-made bread, muffins, fresh fruit, yoghurt and muesli, we discussed the dive sites he would show me. There are some 15 regular sites at Rocktail, almost all within 20 minutes of the launch site. 'We know how lucky we are to be allowed to bring divers into the marine reserve,' Darryl continued, 'and we've got a strict rule on buoyancy control - touch the reef twice and you're back on the boat!'

In my five days at Rocktail Bay, I was careful to stick to the rules. The highlights for me were dives at Gogos' Reef, named after the Zulu word for 'old woman angelfish' because they school there in huge numbers; Solitude - a stunning rock outcrop with deep water all around; and the doughnut-shaped reef at Elusive, where the huge groupers have no fear of divers. One day we met a pair of female humpback whales close inshore. Each had a calf swimming close beside it, and Darryl told me they were going towards Madagascar to give birth to this year's calf in the sheltered waters to the north-west of the island.

With no other dive boats and no-one at all on shore, this was a glimpse of the sea at its best, untainted by man.

Rocktail Bay's five mile beach is separated from coastal forest by 30m-high sand dunes

the area is an important nesting site for loggerhead turtles

a shoal of fusiliers


GETTING THERE: BA, SAA and Virgin all fly daily to Johannesburg from Heathrow. From there it's a one-hour domestic flight to Richards Bay, the nearest airport, and then a scenic four-hour drive to the lodge. The adventurous (and well-heeled) can take a charter flight aircraft from Richards Bay which will fly you at low level over the dramatic coastline and nature reserves to the bush airstrip about 40 minutes from the lodge. A realistic alternative is to self-drive from Johannesburg - allow about seven and a half hours.
DIVING AND ACCOMMODATION: Rocktail Bay is an eco-friendly bush lodge with just 11 extremely comfortable forest chalets. It is run by Wilderness Safaris (www.wilderness-safaris.com) and costs about£100 per person per night. Diving costs 250 Rand (about £16) for the first dive, R200 thereafter. Diving should be pre-booked with Wilderness Safaris because of the small number of divers who can be admitted to the marine reserve each day.
WHEN TO GO: Air temperatures are warm in spring (August-October) and autumn (February-April) and in summer (November-January) conditions are hot and wet. Winter (May-July) is cool and dry and is the most popular time to visit KwaZulu Natal.
WATER TEMPERATURE: Between 23-27?C, warmest between November and April.
DIVING SUITABLE FOR: There are no wrecks and no nitrox. Diving is from a fast RIB and is mostly relatively shallow, around 16-25m. Most dives are drift dives.
FOR NON DIVERS: Chill out on the pristine beaches and take nature walks and drives along the picturesque coastline.
COST: Southern Africa specialist Rainbow Tours (020 7226 1004) offers six nights' full board at Rocktail Bay from £1745. This includes all meals, guided walks and beach activities, as well as flights from London (midweek departure) on SAA with connections to Richards Bay and overland transfers.
FURTHER INFORMATION: South African Tourism, 0870 155 0044, www.south-african-tourism.org